Tell me about: sealed bearings

[Jonny69]

I'm building up a set of wheels. I have my new track hubs here but I've never encountered sealed bearings before. I must say, they are very very smooth running compared to the crusty old cup bearings I'm used to tinkering with.

What do I do with these things? Do you maintain them like old bearings and re-pack them with grease or do you chuck them away when they get a bit loose? *spits at the thought*

 

[HDF]

Since they're sealed you can't repack them or adjust them, there's no way grease can get in or out, so grit can't and grind away at the bearings either. You fit the wheels and just leave them, no need for any maintenance of the bearings, and if they do get loose I think you can normally get a replacement from the company and remove the old ones and replace them. But I expect that's many miles away from now.

 

[David B]

The replacement bearings are often a standard industry size (certainly the case for Sachs-Maillard and older Mavic models), and ones made by firms like SKF can be had via engineering supply firms or from electronics firm RS's website for a reasonable price. HDF is spot-on, though, they last ages. The ones on my Hope front hub are the originals it came with nearly 10 years ago and still running smoothly.

David

 

[Jonny69]

I see, thanks chaps

 

[FluffyChicken]

did and stuff does get in though.

You can left the seals (if actually sealed, not all cartridge bearings are) and rins out the grease and repack if you want.

While they are not a smooth and often effected by miss-alignment as cup/cone etc.. they are easy. If your hubs are quality and have alignment all the better, Mavic had adjustment.

You knock them out and tap new ones in. Best to get a shop to do it with bearing setting tools as hitting the outer edge and not the middle damages the bearings (well the races and cage inside).
Most socket sets (the alternate method) are chamfered in the middle and so don't support the middle race... anyways wittering to much without going in to detail.. come to that in a few years time if they are getting worn

 

[Jonny69]

That's alright, I'm a classic car tinkerer and engine tuner in my spare time. I'm well used to replacing bearings

I just didn't want to dismantle my brand new hubs to see how they worked

 

[FluffyChicken]

That's alright, I'm a classic car tinkerer and engine tuner in my spare time. I'm well used to replacing bearings

I just didn't want to dismantle my brand new hubs to see how they worked

IT'll get the better of you and the hubs'll be apart

What sort of classics ?